Cellulose organic ester composition containing derivatives of dethylene glycol



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Patented Feb. 13, 1934 UNITED STATES PATENT OFFICE CELLULOSE ORGANIC ESTER COMPOSITION CONTAINING DERIVATIVES OF DIETHYL- ENE GLYCOL Thomas F. Murray, Jr., and William 0. Kenyon, Rochester, N. Y., assignors to Eastman Kodak Company, Rochester, N. Y., a corporation of New York No Drawing. Application June 6, 1933 Serial No. 674,542

7 Claims.

This invention relates to compositions of matter in which cellulose organic esters, such as cellulose acetate, are combined or mixed with other substances, such as a compatible plasticizer, with or without a common solvent for both, and with or without other useful addition agents, so that the resulting product will have properties such as will make the composition highly advantageous for use in the plastic and analogous arts, such, for instance, as the manufacture of wrapping sheets or tissue, photographic film, molding compounds and molded products, artificial silk, varnishes or lacquers, coating compositions and the like.

One object of this invention is to produce compositions of matter which may be made into permanently transparent, strong and flexible sheets or films of desired thinness which are substantially waterproof, are unaffected by ordinary photographic fluids and possess the desired properties of a support for sensitive photographic coatings. Another object of our invention is to produce compositions of matter which are capable of easy and convenient manipulation in the plastic and analogous arts, such as in the manufacture of sheets, films, artificial silk filaments, varnishes, lacquers and the like, and to produce compositions which will not injure, or be injured by, the substances or surfaces with which they are associated during manufacture. Still another object of our invention is to produce compositions of matter containing cellulose acetate which have a high degree of flexibility, softness and pliability. Other objects will become apparent to those skilled in the art to which this invention pertains.

While cellulose acetate has been known for decades, it has also been known that to utilize it in the various plastic arts it is necessary to mix therewith various plasticizing or conditioning agents. Certain of these and other addition agents are also added for the purpose of reducing the inflammability of the product. Plastic inducing agents, such as the higher alcohols and their esters, are sometimes also added. Similarly, addition compounds of various kinds have been employed to increase flexibility, transparency, toughness and other properties which will enhance the value of the resulting product. Addition products for the same or similar purposes are also added to cellulose acetate to prepare it for use in the other plastic arts, such as in the manufacture of lacquers, varnishes, artificial silk filaments, molded compounds and the like. While the plasticizers or other addition agents heretofore discovered have had their utility in the art, the increasing use to which cellulose acetate has been put and the increasing number of desirable properties required of cellulose acetate for most purposes have made the discovery of new and economical plasticizers or other addition agents a matter of considerable importance to the art. This has been a problem of some difliculty, since many of the nitrocellulose solvents are not solvents for cellulose acetate, and many substances which act as plasticizers for nitrocelullose are not compatible or at least not sumciently compatible with cellulose acetate to be used as plasticizers in cellulose acetate compositions.

We have discovered that valuable properties may be induced in and/or contributed to compositions containing organic esters of cellulose, such as cellulose acetate, by adding thereto as a plasticizing compound a derivative of diethylene glycol selected from the group consisting of B-phenoxy B'-chloro ethyl ether, B-tetrahydrofurfuroxy B-chloro ethyl ether, and BB'-di (tetrahydrofurfuroxy) ethyl ether. The particularly useful properties which these compounds induce in or contribute to cellulosic compositions containing them are hereinafter enumerated.

B-phenoxy B'-chloro ethyl ether may be prepared as follows. 72 grams of BB-dichloroethyl ether, 100 grams of phenol, 100 cc. of a 40% aqueous solution of sodium hydroxide, and 0.5 gram of copper powder are refluxed together for 1 hours and then allowed to stand for 16 hours without further heating. A salt separates. This is dissolved by the addition of water, whereupon an oil separates, which is extracted with ether. The ethereal solution is dried over calcium chloride and filtered. The ether is distilled off, after which the oil remaining behind is distilled under reduced pressure. B-phenoxy B'-chloro ethyl ether distills over between 161 and 171 C. at 19-20 mm. pressure. It has the formula CsI-Is.O.CH2.CH2.0.CH2.CH2.C1.

B-tetrahydrofurfuroxy B -chloro ethyl ether and BB'-di (tetrahydrofurfuroxy) ethyl ether may be made in the same manner, tetrahydrofurfuryl alcoholbeing used in place of phenol. The two compounds are formed together, and separated in the vacuum distillation, B-tetrahydrofurfuroxy B-chloro ethyl ether distilling at 195 C. at 13 mm. pressure and BB-di (tetrahydrofurfuroxy) ethyl ether at 195-220 C. at 13 mm. pressure.

In order that those skilled in this art may better understand our invention we would state, by

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way of illustration, that for the manufacture of photographic film base or other sheets our new compositions of matter may be compounded as follows: 100 parts of acetone-soluble cellulose acetate, i. e. cellulose acetate containing from about 36% to 42% acetyl radical, approximately, is dissolved with stirring at atmospheric temperature in 300 to 500 parts, preferably 400 parts, by weight, of acetone. To this solution may be added from 20 to 50 parts of B-phenoxy B'-chloro ethyl ether, or approximately 20 parts of B-tetrahydrofurfuroxy B-chloro ethyl ether or of BB-di (tetrahyclrofurfuroxy) ethyl ether. Within the limits stated, the amount of plasticizer may be decreased or increased, depending upon whether it is desired to decrease or increase, respectively, the properties which these plasticizers contribute to the finished product. The amount of solvent employed may also be increased or decreased, depending upon whether it is desired to have a more or less freely flowing composition, respectively.

A composition of matter prepared as above described may be deposited' upon any suitable filmforming surface and the acetone evaporated therefrom to form a film or sheet, in a manner well known to those skilled in the art. A film so produced has permanently brilliant transparency and low inflammability, burning no more readily than ordinary newsprint. Films or sheets produced in accordance with our invention are tough and flexible. For instance, films of cellulose acetate plasticized with from 20% to 50% (20 to 50 parts by weight based on the cellulose acetate) of B-phenoxy B'-chloro ethyl ether had an initial flexibility of from 200% to 600% greater than that of film containing no plasticizer. Furthermore, film so plasticized maintains flexibility in a superior fashion. For instance, at 65 C. films containing from 20 to 50% of B-phenoxy B'-chloro ethyl ether maintained flexibility for over 250 days, whereas an unplasticized film became brittle in 30 days. This indicates that films or sheets so plasticizecl will withstand ordinary usage satisfactorily for many years. Cellulose acetate sheets or films containing B-tetrahydrofurfuroxy B- chloro ethyl ether or BB'-di (tetrahydrofurfuroxy) ethyl ether have the property of transmitting ultra-violet light.

Other similar solvents (instead of acetone) which are compatible with the cellulose acetate and our new plasticizers will also occur to those skilled in this art, such as ethylene chloride-alcohol mixtures. In like manner these plasticizers may be compounded with other single organic esters of cellulose, such as cellulose propionate, butyrate, stearate and the like, or with mixed organic esters, such as cellulose aceto-stearate, cellulose aceto-propionate, cellulose aceto-butyrate or the like, a suitable solvent which will dissolve both the cellulosic derivative and the plasticizer being employed, such, for instance, as an alkylene chloride with or without the addition of alcohol.

Inasmuch as our above-described compositions of matter are useful in the production of films and sheets, it will be apparent that our new plasticizers may also be employed with advantage in the other branches of the plastic art. For instance, our novel plasticizers may be employed with advantage in connection with a number of the known lacquer and varnish f ormula with which they may be found to be compatible. In such cases the plasticizer is usually first put into solution in the cellulose derivative solution, and if non-solvents are added for the purpose of cheapening the composition they are added only to such an extent as will not precipitate the derivative from solution. Other uses within the scope of our invention will also suggest themselves to those skilled in the art and are to be included within the scope of the claims appended hereto.

Moreover, we have found that, upon the addition to cellulose acetate of approximately 100% of B-phenoxy B'-chloro ethyl ether, quite unexpected compatibility of the plasticizer with the cellulose acetate exists and also that quite unexpected flexibility, plasticity and clarity of the final product result. Contrary to experience in most cases where such a large proportion of plasticizer is used, no exudation or crystallizing out of the plasticizer occurs. Compositions containing approximately 100% of B-phenoxy B'chloro ethyl ether have great utility where a highly flexible compound is desired, such as in the coating of a base (for instance, cloth or other fabric) in the production of artificial leather, or in the production of relatively thin sheets wherein more than the usual flexibility is important. Such a composition, if converted, for instance, into sheet form will be found to be supple and non-rigid, and to have the ability to conform readily to a surface upon which it may be placed, and this even at atmospheric temperatures.

These novel compositions of matter are produced by merely mixing the plasticizer with cellulose acetate and then adding suflicient of a common solvent, such as acetone, whereupon an intimate mixture of the plasticizer with the cellulose acetate results. The amount of acetone or other common solvent to be employed varies, of coures, within rather wide limits depending upon the fluidity of the composition desired. 100 parts of acetone will sufiice for some purposes, although we prefer to use 400 parts. Various high boilers or evaporation retardents, such as ethyl lactate, amyl acetate or the like may also be added if desired, as is well known in this art.

The compositions of matter so produced may then be coated into sheets in the usual way by depositing them upon plates or rolls and permitting the solvent to evaporate. If our novel compositions are to be employed in the manufacture of artificial leather, they may be coated upon, for instance, a cloth support and the solvent permitted to evaporate, or the cloth support may be caused to pass through the cellulose acetate-plasticizer composition and permitted to absorb the solution, the solvent in the coating being then permitted to evaporate. In either case, the solvent may, of course, be recovered if desired by condensing the vapors, etc.

While above and in certain of the claims appended hereto, we have referred to the use of a plasticizer in approximately equal proportions, namely in a ratio of approximately 100%, it will be understood that within this terminology variations of from 10% to 15% less than 100% of plasticizer and as much as 25% to 50% more than 100% of the plasticizer may in some instances be desirable.

What we claim as our invention and desire to be secured by Letters Patent of the United States 1. A composition of matter comprising a cellulose organic ester and B-phenoxy B'-chloro ethyl ether.

2. A composition of matter comprising cellulose acetate and B-phenoxy B-chloro ethyl ether.

3. A composition of matter comprising 100 parts of cellulose acetate and about 20 to 100 parts, by weight, of B-phenoxy B-chloro ethyl ether.

106. COMPOSITIONS,

COATING OR PLASTIC.

acetate-propionate and B-phenoxy B'-chloro ethyl ether.

'7. A composition of matter comprising cellulose acetate-butyrate and B-phenoxy B-ch1or0 ethyl ether.

THOMAS F. MURRAY, JR. WILLIAM O. KENYON. 

